In order to improve the efficiency and increase the distance of the wireless power transmission system, metamaterials were applied. The formula derivation and simulation analysis verified the ability of metamaterials to improve the transmission efficiency respectively from the point of view of negative refraction and the evanescent wave. It is concluded that negative permeability can enhance the magnetic field and exponentially increase the coupling coefficient, while negative permittivity can only make little contribution to the coupling coefficient; and that the focusing effect caused by negative refraction cannot improve transmission efficiency under the radio band within a couple of centimeters. The matematerials with single negative permeability is good enough to improve the efficiency.